Method for transmitting packets in a mobile station

ABSTRACT

A method of performing uplink transmission at a user equipment (UE) is provided. The UE determines whether a hybrid automatic repeat request (HARQ) retransmission collides with a transmission for a random access in a time interval, and performs the HARQ retransmission when the HARQ retransmission does not collide with the transmission for random access in the time interval. A current value of information indicating a redundancy version (RV) for the HARQ retransmission is incremented by 1 when the HARQ retransmission does not collide with the transmission for random access in the time interval.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.14/307,270, filed Jun. 17, 2014 (now U.S. Pat. No. 9,173,236 issued onOct. 27, 2015), which is a Continuation of U.S. patent application Ser.No. 13/932,868, filed on Jul. 1, 2013 (now U.S. Pat. No. 8,787,326,issued on Jul. 22, 2014), which is a Continuation of U.S. patentapplication Ser. No. 12/681,734, filed on Apr. 5, 2010 (now U.S. Pat.No. 8,498,274, issued on Jul. 30, 2013), which is the National Phase ofPCT International Application No. PCT/KR2008/007797, filed on Dec. 30,2008, which claims priority to Korean Patent Application No.10-2008-0002630, filed Jan. 9, 2008. The entire contents of all of theabove applications are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

Technical Field

The present invention relates to a 3^(rd) generation partnership project(3GPP) long term evolution (LTE) system, and more particularly, to amethod of avoiding or adjusting collision when a resource allocated to apacket which will be transmitted by a mobile station collides with aspecial-purpose resource.

Background Art

In a cellular radio packet transmitting system using an orthogonalfrequency division multiple access (OFDMA) scheme or a singlecarrier-frequency division multiple access (SC-FDMA) scheme used inuplink, uplink packets are distinguished by utilizing differenttime-frequency resources. In particular, in the transmission of theuplink packets of the cellular system, a base station transmitsscheduling commands to mobile stations such that collision in uplinkpacket transmissions of different mobile stations is avoided and packettransmission suitable for a buffer state and a channel state of eachmobile station is realized.

However, if an uplink packet scheduling command is transmitted indownlink whenever the uplink packet is transmitted, downlink overhead isextremely increased. Accordingly, in order to reduce downlink overheadin uplink packet transmission scheduling, a synchronous hybrid automaticrepeat request (HARQ) scheme and a persistent scheduling scheme may beconsidered.

In the synchronous HARQ scheme, a mobile station performs a packettransmission according to a scheduling command received from a basestation and performs a packet retransmission with respect to a packetfor which negative acknowledgement (NACK) is received from the basestation, using a previously used frequency band after a predeterminedtime elapses from a previous transmission timing or using a frequencyband moved by the amount induced from a predetermined frequency hoppingpattern if frequency hopping is further applied. Alternatively, a mobilestation which receives a plurality of time-frequency resources availablefor a packet transmission in the future from a base station in advance,that is, a mobile station which receives persistent scheduling mayperform a packet transmission using a predetermined time-frequencyresource although a scheduling command is not received.

Several subpackets used for an initial transmission and a retransmissionusing the HARQ scheme are created from one codeword packet. The createdseveral subpackets can be distinguished by the lengths of the subpacketsand the start locations of the subpackets. A distinguishable subpacketis called a redundancy version (RV) and RV information refers to apromised start location of each RV.

A transmitter (Tx) transmits subpackets via a data channel in each HARQtransmission. At this time, the transmitter creates the RV of thesubpacket for each HARQ transmission in sequence previously decidedbetween the transmitter and a receiver or creates any RV and transmitsRV information via a control channel. The receiver (Rx) maps thesubpacket received via the data channel to an accurate location of acodeword packet in a predetermined RV sequence or using the RVinformation received via the control channel.

FIG. 1 is a view showing a HARQ transmission in case of using four fixedRV start locations. In addition, in FIG. 1, it is assumed that a staticchannel is used and the size of the subpacket used in each HARQtransmission is constant and is N/3. In FIG. 1, a first transmissionindicates a subpacket used for an initial transmission using the HARQscheme and the remaining transmissions indicate subpackets used forthree HARQ retransmissions. In FIG. 1, N indicates the size of acircular buffer.

The base station may control a transmission of the mobile station, whichreceives dynamic scheduling, via an uplink scheduling command withrespect to a new data packet of each mobile station, but may nottransmit a scheduling command with respect to a retransmission packet.At this time, the mobile station performs a packet retransmission withrespect to data, which is requested to be retransmitted from the basestation, at a subframe separated from a previous packet transmissiontiming of the same data by a predetermined subframe interval. However,the mobile station detects whether the scheduling command is transmittedto the mobile station in downlink with respect to all the uplinksubframes and performs a packet retransmission according to the commandif the uplink scheduling command for the data to be retransmitted isdetected.

In the persistent scheduling scheme, the base station allocates thetime-frequency resource to the mobile station in a specific period inadvance such that the time-frequency resource is used for the uplinkpacket transmission. The mobile station to which the persistentscheduling is applied may transmit an uplink packet with respect to thescheduled time-frequency resource although the scheduling command is notreceived.

In addition, the mobile stations in which the uplink packettransmissions are previously configured by upper-layer signaling likethe persistent scheduling scheme may transmit packets using thepredetermined time-frequency resources without the downlink schedulingcommand. When the retransmission is necessary with respect to thepackets transmitted using the predetermined time-frequency resources,the synchronous HARQ operation may be applied.

A part of the uplink time-frequency resource in the cellular radiopacket transmitting system may be reserved for a special purpose. As arepresentative example thereof, a time-frequency resource which isreserved such that the mobile stations which attempt to perform initialconnection to a cell transmit a signal which is first transmitted in thecell, that is, a random access channel (RACH), may be used.

The mobile stations which attempt to perform the connection to the cellmay transmit a physical RACH (PRACH) using a unit time-frequency domainoccupying one or two subframes in about a 1.08-MHz band reserved for aPRACH transmission. The unit time-frequency domain for the PRACHtransmission may be allocated according to one of 16 PRACHconfigurations shown in Table 1.

TABLE 1 PRACH System frame Configuration number Subframe number 0 Even 11 Even 4 2 Even 7 3 Any 1 4 Any 4 5 Any 7 6 Any 1, 6 7 Any 2, 7 8 Any 3,8 9 Any 1, 4, 7 10 Any 2, 5, 8 11 Any 3, 6, 9 12 Any 0, 2, 4, 6, 8 13Any 1, 3, 5, 7, 9 14 Any 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 15 Even 9

In Table 1, one system frame consists of 10 subframes, and 10 subframesin the system frame are denoted by subframe numbers of 0 to 9. At thistime, the frequency location for a PRACH transmission in each subframemay move according to a predetermined frequency hopping pattern.

If specific time-frequency resources are reserved for special purpose,the transmission area for retransmission packets to be transmitted bythe synchronous HARQ scheme and the packets to be transmitted by thepersistent scheduling scheme may collide with the time-frequencyresource reserved for the special purpose.

FIG. 2 is a view showing an example in which time-frequency resourcesfor retransmitting the packets by the synchronous HARQ scheme collidewith time-frequency resources reserved for a RACH transmission.

In the example of FIG. 2, the packets are retransmitted by thesynchronous HARQ scheme in the unit of four subframes. Boxes 290occupying four resource blocks on a frequency axis indicate thetime-frequency resources reserved for the RACH transmission. At thistime, resources 210 and 220 allocated to an initial transmission packetand a retransmission packet are shown at the upper side of FIG. 2 andresources 230, 240 and 250 allocated to an initial transmission packet,a first retransmission packet and a second retransmission packet areshown at the lower side of FIG. 2. A RACH time-frequency resource 290collides with a first retransmission packet 220 and a secondretransmission packet 250 shown at the upper side.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a method of avoiding oradjusting collision if a retransmission packet transmitted by a mobilestation using a synchronous HARQ scheme or a packet transmitted using apreviously allocated resource by an upper layer is overlapped with aresource reserved for another purpose in a cellular radio access methodin which packet transmissions of different mobile stations aredistinguished by different frequency bands in the same duration.

The object of the present invention can be achieved by providing amethod of transmitting uplink data using a resource allocated to amobile station, the method including: determining whether a resourcereserved for a special purpose is overlapped with a resource fortransmitting a packet by the mobile station, on the basis of resourceallocation information on the mobile station; and delaying thetransmission of the packet if the reserved resource is overlapped withthe resource for transmitting the packet.

In the delaying of the transmission of the packet, the transmission ofthe whole packet may be delayed even when the resource for transmittingthe packet is partially overlapped with the reserved resource.

The resource reserved for the special purpose may include a resourcereserved for a random access channel (RACH) transmission.

The resource allocated to the mobile station may be allocated by apersistent scheduling scheme.

The packet may be a synchronous hybrid automatic repeat request (HARQ)retransmission packet. In the transmitting of the packet at the nextretransmission timing, a redundancy version of a previous transmissiontiming may be transmitted at the next retransmission timing.

In another aspect of the present invention, provided herein is a methodof transmitting uplink data using a resource allocated to a mobilestation, the method including: determining whether a resource reservedfor a special purpose is overlapped with a resource for transmitting apacket by the mobile station, on the basis of resource allocationinformation on the mobile station; and partially transmitting the packetusing the residual resource excluding the overlapped resource if thereserved resource is partially overlapped with the resource fortransmitting the packet.

The resource reserved for the special purpose may include a resourcereserved for a random access channel (RACH) transmission.

In another aspect of the present invention, provided herein is a methodof transmitting uplink data using a resource allocated to a mobilestation, the method including: determining whether a resource reservedfor a special purpose is overlapped with a resource for transmitting apacket by the mobile station, on the basis of resource allocationinformation on the mobile station, when system information including acollision avoidance instruction is received from a base station; anddelaying the transmission of the packet if the reserved resource isoverlapped with the resource for transmitting the packet.

The system information may be information broadcasted by the basestation.

The resource reserved for the special purpose may include a resourcereserved for a random access channel (RACH) transmission.

In another aspect of the present invention, provided herein is a methodof transmitting uplink data using a resource allocated to a mobilestation, the method including: determining whether a resource reservedfor a special purpose is overlapped with a resource for transmitting apacket by the mobile station, on the basis of resource allocationinformation on the mobile station, when system information including acollision avoidance instruction is received from a base station; andpartially transmitting the packet using the residual resource excludingthe overlapped resource if the reserved resource is partially overlappedwith the resource for transmitting the packet.

The resource reserved for the special purpose may include a resourcereserved for a random access channel (RACH) transmission.

According to the embodiments of the present invention, it is possible toincrease uplink packet transmission efficiency without increasingdownlink overhead, by avoiding or adjusting collision of an uplinkpacket transmission with a time-frequency resource reserved for anotherpurpose.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention, illustrate embodiments of the inventionand together with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a view showing a packet transmission in case of using fixed RVstart locations in a synchronous HARQ.

FIG. 2 is a view showing an example in which resources forretransmitting packets by a synchronous HARQ scheme collide withresources reserved for a RACH transmission.

FIG. 3 is a flowchart illustrating a method of transmitting packets in amobile station according to an embodiment of the present invention.

FIG. 4 is a flowchart illustrating a method of transmitting packets in amobile station according to another embodiment of the present invention.

FIG. 5 is a flowchart illustrating a method of transmitting packets in amobile station according to another embodiment of the present invention.

FIG. 6 is a flowchart illustrating a method of transmitting packets in amobile station according to another embodiment of the present invention.

FIG. 7 is a view showing an example of transmitting packets according tothe method of FIG. 3.

FIG. 8 is a view showing an example of transmitting packets according tothe method of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. However, the following embodiments of the present inventionmay be variously modified and the range of the present invention is notlimited to the following embodiments.

The embodiments of the present invention provides a method of avoidingor adjusting collision when an uplink packet transmission collides witha resource reserved for a special purpose, for example, a RACHtime-frequency resource.

FIG. 3 is a flowchart illustrating a method of transmitting packets in amobile station according to an embodiment of the present invention.

Hereinafter, it is assumed that a part of a resource necessary for theuplink transmission of the mobile station is allocated in advance like apersistent scheduling scheme, or a resource allocated to a packet whichwill be transmitted by the mobile station is decided according to asynchronous HARQ scheme.

It is determined whether a resource reserved for a special purpose isoverlapped with a resource for transmitting a packet by the mobilestation, on the basis of resource allocation information on the mobilestation (S310).

At this time, if the resource reserved for the special purpose isoverlapped with the resource for transmitting the packet, thetransmission of the packet is delayed such that the packet istransmitted by a next allocated resource in the persistent schedulingscheme and is transmitted at a next retransmission timing in thesynchronous HARQ scheme (S320). Preferably, in this step S320, even whenthe resource for transmitting the packet is partially overlapped withthe reserved resource, the transmission of the packet may be delayed tothe next retransmission timing.

At this time, if the reserved resource is not overlapped with theresource for transmitting the packet, the packet is normally transmitted(S330).

In the method of transmitting the packets in the mobile stationaccording to the embodiment of the present invention, the uplinkretransmission packet transmission colliding with the special-purposetime-frequency resource is delayed to a next synchronous HARQtransmission timing. Alternatively, if the same time-frequency resourceas the special-purpose time-frequency resource is allocated by thepersistent scheduling scheme, the packet is not transmitted by thattime-frequency resource.

FIG. 4 is a flowchart illustrating a method of transmitting packets in amobile station according to another embodiment of the present invention.

It is determined whether a resource reserved for a special purpose isoverlapped with a resource for transmitting a packet by the mobilestation, on the basis of resource allocation information on the mobilestation (S410).

At this time, if the resource reserved for the special purpose ispartially overlapped with the resource allocated to the packet, thepacket is partially transmitted using the residual resource excludingthe overlapped resource (S420). Preferably, in this step S420, if thereserved resource is entirely overlapped with the resource allocated tothe packet, the transmission of the packet is delayed such that thepacket is transmitted by a next allocated resource in the persistentscheduling scheme and is transmitted at a retransmission timing in thesynchronous HARQ scheme.

The method of partially transmitting the packet using the residualresource is, for example, as follows: a first method of extracting acomplete packet which will be transmitted at a retransmission timingfrom a buffer and removing a part overlapped with the reserved resourcefrom the extracted packet; and a second method of extracting a shortpacket in consideration of a part overlapped with the reserved resourcewhen a complete packet which will be transmitted at a retransmissiontiming is extracted from a buffer. However, these methods are onlyexemplary and the method of partially transmitting the packets if thereserved resource is partially overlapped with the resource allocated tothe packet according to the embodiment of the present invention is notlimited to the above-described methods.

If the reserved resource is not overlapped with the resource allocatedto the packet, the packet is normally transmitted (S430).

A RACH signal is not always transmitted by the time-frequency resourcereserved for a RACH transmission and a probability in which the RACHsignal is transmitted is changed according to the number of mobilestations which attempt to access a cell. Accordingly, collision may beready to be endured instead of avoiding the transmission of the packetby the mobile station using the RACH time-frequency resource.Alternatively, the base station may transmit a scheduling command to themobile station with respect to the time-frequency resources, in whichcollision is expected to occur, such that the collision does not occur.

Hereinafter, a method of, at the base station, informing a mobilestation or all mobile stations in a cell whether or not the packettransmission using the time-frequency resource reserved for the RACH isavoided via signaling of at least one bit.

FIG. 5 is a flowchart illustrating a method of transmitting packets in amobile station according to another embodiment of the present invention.

First, it is determined whether system information including a collisionavoidance instruction is received from the base station (S505). Thecollision avoidance instruction indicates the signaling of the basestation.

If the mobile station receives the system information including thecollision avoidance instruction, it is determined whether a resourcereserved for a special purpose is overlapped with the resource fortransmitting the packet by the mobile station, on the basis of resourceallocation information on the mobile station (S510). If the mobilestation does not receive the system information including the collisionavoidance instruction, the packet is normally transmitted at atransmission timing (S530).

At this time, if the reserved resource is overlapped with the resourceallocated to the packet, the transmission of the packet is delayed suchthat the packet is transmitted by a next allocated resource in thepersistent scheduling scheme and is transmitted at a next retransmissiontiming in the synchronous HARQ scheme (S520).

At this time, if the reserved resource is not overlapped with theresource allocated to the packet, the packet is normally transmitted(S530).

FIG. 6 is a flowchart illustrating a method of transmitting packets in amobile station according to another embodiment of the present invention.

First, it is determined whether system information including a collisionavoidance instruction is received from the base station (S605). Thecollision avoidance instruction indicates the signaling of the basestation.

If the mobile station receives the system information including thecollision avoidance instruction, it is determined whether a resourcereserved for a special purpose is overlapped with the resource fortransmitting the packet by the mobile station, on the basis of resourceallocation information on the mobile station (S610). If the mobilestation does not receive the system information including the collisionavoidance instruction, the packet is normally transmitted at atransmission timing (S630).

At this time, if the reserved resource is partially overlapped with theresource allocated to the packet, the packet is partially transmittedusing the residual excluding the overlapped resource (S620).

At this time, if the reserved resource is not overlapped with theresource allocated to the packet, the packet is normally transmitted(S630).

FIG. 7 is a view showing an example of transmitting synchronous HARQretransmission packets according to the method of FIG. 3.

In the examples of FIGS. 7 and 8, each packet is retransmitted by thesynchronous HARQ scheme in the unit of four subframes.

In FIG. 7, boxes 790 occupying four resource blocks on a frequency axisindicate time-frequency resources reserved for a RACH transmission. Atthis time, resources 710 and 720 allocated to an initial transmissionpacket and a retransmission packet are shown at the upper side of FIG. 7and resources 730, 740 and 750 allocated to an initial transmissionpacket, a first retransmission packet and a second retransmission packetare shown at the lower side of FIG. 7.

The first retransmission packet 720 of the upper side and the secondretransmission packet 750 of the lower side colliding with the RACHtime-frequency resource 790 are not transmitted at a currenttransmission timing and are transmitted at a next retransmission timing.

In case that retransmission packet at a mobile station is decided to bea certain part of whole coding data in consideration of retransmissiontiming (e.g., HARQ scheme defining RV is used), the coding data to betransmitted by the delayed retransmission packet may be decided on thesame criterion as the case where the packet transmission is not delayed.In FIG. 7, numerals denoted in the packets represent the RV and RV=0,RV=1, RV=2, . . . indicate coding data parts which are previouslydecided to be transmitted at an initial transmission timing, a firstretransmission timing, a second retransmission timing, . . . .

In the packet transmission in which the time-frequency for the packetpartially collides with the special-purpose time-frequency resource, apart of the whole coding data may be transmitted using thetime-frequency resource which does not collide.

FIG. 8 is a view showing an example of transmitting a synchronous HARQretransmission packet according to the method of FIG. 4.

In FIG. 8, boxes 890 occupying four resource blocks on a frequency axisindicate time-frequency resources reserved for a RACH transmission. Atthis time, resources 810 and 820 allocated to an initial transmissionpacket and a retransmission packet are shown at the upper side of FIG. 8and resources 830, 840 and 850 allocated to an initial transmissionpacket, a first retransmission packet and a second retransmission packetare shown at the lower side of FIG. 8.

In order to prevent collision with the RACH time-frequency resource 890,the first retransmission packet 820 of the upper side is transmitted ata next retransmission timing. Meanwhile, if a partial time-frequencyresource for the second retransmission packet 850 is overlapped with theRACH time-frequency resource 890, the transmission of the packet is notdelayed and a part of the packet is transmitted using the residualresource excluding the overlapped resource.

In this case, when the HARQ scheme, that decides which part of wholecoding data corresponds to the packet to be retransmitted by the mobilestation in consideration of retransmission timings, is used, theexisting scheme may be applied without alteration. The secondretransmission packet 850 of the lower side of FIG. 8 may beretransmitted in the existing RV sequence even when the time-frequencyresource available for the retransmission is reduced compared with aprevious transmission like the retransmission of a packet of RV=2. Atthis time, each RV is defined regardless of the size of the transmissionpacket, like a start bit location in the whole coding data bit stream.

The above embodiments are provided by combining components and featuresof the present invention in specific forms. The components or featuresof the present invention should be considered optional if not explicitlystated otherwise. The components or features may be implemented withoutbeing combined with other components or features. The embodiments of thepresent invention may also be provided by combining some of thecomponents and/or features. The order of the operations described abovein the embodiments of the present invention may be changed. Somecomponents or features of one embodiment may be included in anotherembodiment or may be replaced with corresponding components or featuresof another embodiment. It will be apparent that claims which are notexplicitly dependent on each other can be combined to provide anembodiment or new claims can be added through amendment after thisapplication is filed.

The above embodiments of the present invention have been describedfocusing mainly on the data communication relationship between a mobilestation and a Base Station (BS). Specific operations which have beendescribed as being performed by the BS may also be performed by uppernodes as needed. That is, it will be apparent to those skilled in theart that the BS or any other network node may perform various operationsfor communication with terminals in a network including a number ofnetwork nodes including BSs. The term “base station (BS)” may bereplaced with another term such as “fixed station”, “Node B”, “eNode B(eNB)”, or “access point”. The term “mobile station” may also bereplaced with another term such as “user equipment (UE)”, “terminal”, or“mobile subscriber station (MSS)”.

The embodiments of the present invention can be implemented by hardware,firmware, software, or any combination thereof. Various embodiments ofthe present invention may be implemented by one or more applicationspecific integrated circuits (ASICs), digital signal processors (DSPs),digital signal processing devices (DSPDs), programmable logic devices(PLDs), field programmable gate arrays (FPGAs), processors, controllers,microcontrollers, microprocessors, or the like.

Various the embodiments of the present invention may also be implementedin the form of software modules, processes, functions, or the like whichperform the features or operations described above. Software code can bestored in a memory unit so that it can be executed by a processor. Thememory unit may be located inside or outside the processor and cancommunicate data with the processor through a variety of known means.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

The present invention provides a method of avoiding or adjustingcollision when a resource allocated to a packet which will betransmitted by a mobile station collides with a special-purposeresource. The present invention is applicable to a device associatedwith a mobile communication system, such as a mobile station or a basestation, and an algorithm associated therewith.

The invention claimed is:
 1. A method for performing an uplinktransmission, the method comprising: determining, by a user equipment(UE), whether or not a hybrid automatic repeat request (HARQ)retransmission collides with a transmission for random access in a timeinterval; and performing, by the UE, the HARQ retransmission when theHARQ retransmission does not collide with the transmission for randomaccess in the time interval, wherein a current value of informationindicating a redundancy version (RV) for the HARQ retransmission isincremented by 1 when the HARQ retransmission does not collide with thetransmission for random access in the time interval.
 2. The methodaccording to claim 1, further comprising: performing the transmissionfor random access and skipping the HARQ retransmission when the HARQretransmission collides with the transmission for random access in thetime interval.
 3. The method according to claim 1, further comprising:when the HARQ retransmission collides with the transmission for randomaccess in the time interval, performing the HARQ retransmission in anext retransmission time interval.
 4. The method according to claim 3,wherein the HARQ retransmission in the next retransmission time intervalis performed on a same resource as previously assigned.
 5. The methodaccording to claim 3, wherein the HARQ retransmission in the nextretransmission time interval is performed according to an uplinkscheduling command detected in the next retransmission time interval. 6.The method according to claim 1, wherein the time interval correspondsto a subframe.
 7. The method according to claim 1, wherein theinformation indicating the RV has a value of 0 for an initial HARQtransmission.
 8. A user equipment configured to perform an uplinktransmission, the user equipment comprising: a memory; and a processoroperatively connected to the memory and configured to: determine whetheror not a hybrid automatic repeat request (HARQ) retransmission collideswith a transmission for random access in a time interval, and performthe HARQ retransmission when the HARQ retransmission does not collidewith the transmission for random access in the time interval, wherein acurrent value of information indicating a redundancy version (RV) forthe HARQ retransmission is incremented by 1 when the HARQ retransmissiondoes not collide with the transmission for random access in the timeinterval.
 9. The user equipment according to claim 8, wherein theprocessor is further configured to: perform the transmission for randomaccess and skip the HARQ retransmission when the HARQ retransmissioncollides with the transmission for random access in the time interval.10. The user equipment according to claim 8, wherein the processor isfurther configured to: perform the HARQ retransmission in a nextretransmission time interval when the HARQ retransmission collides withthe transmission for random access in the time interval.
 11. The userequipment according to claim 10, wherein the HARQ retransmission in thenext retransmission time interval is performed on a same resource aspreviously assigned.
 12. The user equipment according to claim 10,wherein the HARQ retransmission in the next retransmission time intervalis performed according to an uplink scheduling command detected in thenext retransmission time interval.
 13. The user equipment according toclaim 8, wherein the time interval corresponds to a subframe.
 14. Theuser equipment according to claim 8, wherein the information indicatingthe RV has a value of 0 for an initial HARQ transmission.